English3
could not have done 和 must not have done有什么区别啊,could not have done表示对过去已经做的事的一种不可能,那后者?
could not have done 表示不可能做过某事. 表示的是一种可能性.不确定的; must not have done 是肯定没有做过某事. 语气是肯定的
答:Hello,everybody My name is**. I am very happy to see so many colleague. First,l...详情>>